Zygomatic dysmorphology in unicoronal synostosis

School-age outcomes in patients with unilateral coronal synostosis: comparison of fronto-orbital advancement and endoscopic strip craniectomy

OBJECTIVE

Outcomes research on unilateral coronal synostosis is mostly limited to the early postoperative period. This study examines facial asymmetry, desire for revision, and patient-reported outcomes at school age in children who received either endoscopic strip craniectomy with helmet therapy or fronto-orbital advancement (open repair).

METHODS

Patients with repaired unilateral coronal synostosis born between 2000 and 2017, with 3D photographs taken when they were between 3.5 and 8 years of age, were eligible for study inclusion. Three pairs of bilateral linear measurements and two angular measurements were taken. Parent- and physician-reported desire for revision and patient-reported outcomes (Patient-Reported Outcomes Measurement Information System cognitive function and Quality of Life in Neurological Disorders stigma scores) were collected from patient charts.

RESULTS

Thirty-five patients qualified, including 25 with open repair and 10 with endoscopic repair. The median patient ages at repair were 3 months and 8 months in the endoscopic and open groups, respectively. The average ages at final 3D photography were 5.8 years and 5.5 years in the endoscopic and open groups, respectively. Digital anthropometry revealed no significant differences in measures of facial asymmetry between the repair groups (p ≥ 0.211). Midface depth (tragion to subnasale) was significantly less symmetric at school age than other linear measures (F(2,102) = 9.14, p < 0.001). Forehead asymmetry was significantly associated with parent- and physician-reported desire for revision (p ≤ 0.006). No significant associations were found between physical asymmetry and patient-reported stigma or cognitive function (p > 0.046, Holm-Bonferroni correction).

CONCLUSIONS

Children who underwent open or endoscopic repair for unilateral coronal synostosis have comparable facial symmetry at school age, but midface depth remains highly asymmetrical in both groups. Forehead asymmetry at school age correlates with parent- and physician-reported desire for revision.

Weighing In on the Controversy: Preoperative Imaging in Unicoronal Craniosynostosis Leads to Strategic Changes in Surgical Care

BACKGROUND

Clinical findings in children with unilateral coronal craniosynostosis are characteristic, and therefore clinicians have questioned the need for confirmatory imaging. Preoperative computed tomographic imaging is a powerful tool for diagnosing associated anomalies that can alter treatment management and surgical planning. The authors' aim was to determine whether and how routine preoperative imaging affected treatment management in unilateral coronal craniosynostosis patients within their institution.

METHODS

A retrospective, single-center review of all patients who underwent cranial vault remodeling for unilateral coronal craniosynostosis between 2006 and 2014 was performed. Patient data included demographics, age at computed tomographic scan, age at surgery, results of the radiographic evaluation, and modification of treatment following radiologic examination.

RESULTS

Of 194 patients diagnosed with single-suture craniosynostosis, 29 were diagnosed with unilateral coronal craniosynostosis. Additional radiographic anomalies were found in 19 unilateral coronal craniosynostosis patients (65.5 percent). These included severe deviation of the anterior superior sagittal sinus [n = 12 (41.4 percent)], Chiari I malformation [n = 1 (3.4 percent)], and benign external hydrocephalus [n = 2 (6.9 percent)]. The radiographic anomalies resulted in a change in management for 48.3 percent of patients. Specifically, alteration in frontal craniotomy design occurred in 12 patients (41.4 percent), and two patients (6.9 percent) required further radiographic studies.

CONCLUSIONS

Although clinical findings in children with unilateral coronal craniosynostosis are prototypical, preoperative computed tomographic imaging is still of great consequence and continues to play an important role in surgical management. Preoperative imaging enabled surgeons to alter surgical management and avoid inadvertent complications such as damage to a deviated superior sagittal sinus. Imaging findings of Chiari malformation and hydrocephalus also permitted judicious follow-up.

CLINICAL QUESTIONS/LEVEL OF EVIDENCE

Therapeutic, IV.

Proof of Concept Study for the Design, Manufacturing, and Testing of a Patient-Specific Shape Memory Device for Treatment of Unicoronal Craniosynostosis

Treatment of unicoronal craniosynostosis is a surgically challenging problem, due to the involvement of coronal suture and cranial base, with complex asymmetries of the calvarium and orbit. Several techniques for correction have been described, including surgical bony remodeling, early strip craniotomy with orthotic helmet remodeling and distraction. Current distraction devices provide unidirectional forces and have had very limited success. Nitinol is a shape memory alloy that can be programmed to the shape of a patient-specific anatomy by means of thermal treatment.In this work, a methodology to produce a nitinol patient-specific distractor is presented: computer tomography images of a 16-month-old patient with unicoronal craniosynostosis were processed to create a 3-dimensional model of his skull and define the ideal shape postsurgery. A mesh was produced from a nitinol sheet, formed to the ideal skull shape and heat treated to be malleable at room temperature. The mesh was afterward deformed to be attached to a rapid prototyped plastic skull, replica of the patient initial anatomy. The mesh/skull construct was placed in hot water to activate the mesh shape memory property: the deformed plastic skull was computed tomography scanned for comparison of its shape with the initial anatomy and with the desired shape, showing that the nitinol mesh had been able to distract the plastic skull to a shape close to the desired one.The shape-memory properties of nitinol allow for the design and production of patient-specific devices able to deliver complex, preprogrammable shape changes.

Temporal Progression of Craniofacial Dysmorphology in Unilateral Coronal Synostosis: A Mechanistic Hypothesis

AIM

This study chronicles skull base and face development in nonsyndromic unilateral coronal synostosis (UCS) during infancy, to characterize the mechanistic progression of facial dysmorphology.

METHODS

Computed tomography scans from 51 subjects were reviewed (26 UCS, 25 controls) and data were reconstructed. Patients were stratified into 5 age groups. A series of measurements were taken from the reconstructions.

RESULTS

All patients had a unilaterally fused coronal suture at the time of analysis. Asymmetry of the sphenoid wings was present across all age groups. The sphenoid wing ipsilateral to the fused suture consistently had a more acute angle from the midline. At 19 days of age, ipsilateral nasal root and cribriform plate deviation are noted, as well as increased contralateral zygoma antero-posterior length. Patients younger than 2 months also had elongated posterior cranial bases. At 2 to 3 months of age, the cranial base widens in the anterior portion of the middle cranial fossa with an increased ipsilateral pterion to sella distance. The most delayed change observed was the increase in contralateral orbital rim angle at 7 to 12 months of age compared to normal.

CONCLUSION

After suture fusion, sphenoid wing changes are among the earliest restructural malformations to take place. This suggests that the cascade of dysmorphology in UCS originates in the cranial vault, then progresses to the skull base, and lastly to the facial structures. Ipsilateral orbital changes are early facial changes in UCS that begin before 2 months of age. This is then followed by changes in the contralateral face later in development.

Zygomatic bone shape in intentional cranial deformations: a model for the study of the interactions between skull growth and facial morphology

Intentional cranial deformations (ICD) were obtained by exerting external mechanical constraints on the skull vault during the first years of life to permanently modify head shape. The repercussions of ICD on the face are not well described in the midfacial region. Here we assessed the shape of the zygomatic bone in different types of ICDs. We considered 14 non-deformed skulls, 19 skulls with antero-posterior deformation, nine skulls with circumferential deformation and seven skulls with Toulouse deformation. The shape of the zygomatic bone was assessed using a statistical shape model after mesh registration. Euclidian distances between mean models and Mahalanobis distances after canonical variate analysis were computed. Classification accuracy was computed using a cross-validation approach. Different ICDs cause specific zygomatic shape modifications corresponding to different degrees of retrusion but the shape of the zygomatic bone alone is not a sufficient parameter for classifying populations into ICD groups defined by deformation types. We illustrate the fact that external mechanical constraints on the skull vault influence midfacial growth. ICDs are a model for the study of the influence of epigenetic factors on craniofacial growth and can help to understand the facial effects of congenital skull malformations such as single or multi-suture synostoses, or of external orthopedic devices such as helmets used to correct deformational plagiocephaly.

Quantitative analysis of craniofacial dysmorphology in infants with anterior synostotic plagiocephaly

PURPOSE

The study aimed to identify premature synostosis of "major" and "minor" sutures of the coronal sutural arch and splanchnocranium sutures to evaluate the relationship between craniofacial dysmorphology and the sutural pattern in children with anterior plagiocephaly.

METHODS

A quantitative analysis of the skull base and facial changes was performed on preoperative high-resolution CT images in 18 children with anterior synostotic plagiocephaly and compared with imaging findings in 18 age-matched healthy subjects.

RESULTS

All patients had patent splanchnocranium sutures. Fifteen out of 18 children showed early and isolated synostosis of the unicoronal suture (the major suture of the coronal ring) and were classified in groups II and III according to the classification scheme of anterior synostotic plagiocephaly based on the severity of craniofacial dysmorphology. Premature fusion of the unilateral coronal suture in groups II and III caused a marked asymmetry and reduced growth of the anterior and middle fossae on the synostotic side and a secondary varying severity in terms of asymmetric growth of the facial complex. Although both groups showed anterior displacement of the mandibular articulation on the synostotic side, group II showed only maxillary asymmetry, while group III showed maxillary and mandibular asymmetry.

CONCLUSIONS

In anterior synostotic plagiocephaly, the severity of skull base changes and asymmetric growth of the facial complex is not caused by skull base sutural synostotic involvement but is probably related to the different timing of unilateral coronal suture closure.

Facial changes after early treatment of unilateral coronal synostosis question the necessity of primary nasal osteotomy

BACKGROUND

The premature fusion of unilateral coronal suture can cause a significant asymmetry of the craniofacial skeleton, with an oblique deviation of the cranial base that negatively impacts soft tissue facial symmetry. The purpose of this study was to assess facial symmetry obtained in patients with unilateral coronal synostosis (UCS) surgically treated by 2 different techniques. We hypothesized that nasal deviation should not be addressed in a primary surgical correction of UCS.

METHODS

Consecutive UCS patients were enrolled in a prospective study and randomly divided into 2 groups. In group 1, the patients underwent total frontal reconstruction and transferring of onlay bone grafts to the recessive superior orbital rim (n = 7), and in group 2, the patients underwent total frontal reconstruction and unilateral fronto-orbital advancement (n = 5). Computerized photogrammetric analysis measured vertical and horizontal axis of the nose and the orbital globe in the preoperative and postoperative periods. Intragroup and intergroup comparisons were performed.

RESULTS

Intragroup preoperative and postoperative comparisons showed a significant (all P < 0.05) reduction of the nasal axis and the orbital-globe axis in the postoperative period in the 2 groups. Intergroup comparisons showed no significant difference (all P > 0.05).

CONCLUSIONS

Facial symmetry was achieved in the patients with UCS who underwent surgery regardless of surgical approach evaluated here. Our data showed a significant improvement in nasal and orbital-globe deviation, leading us to question the necessity of primary nasal correction in these patients.

Cross-specialty developments: a summary of the mutually relevant recent literature from the journal of plastic, reconstructive and aesthetic surgery

Keeping abreast of current developments is increasingly challenging when the volume of specialty articles being published is rising exponentially, and it is most acute when surgical specialties overlap, as in the case of head, neck, and facial reconstructive surgery. Here, the potential for missing key developments presents a compelling case for a summary article that highlights articles likely to be of mutual relevance. We evaluated 129 original studies and 6 reviews published in the Journal of Plastic, Reconstructive, and Aesthetic Surgery between September 2012 and August 2014, and summarised the main papers of interest and merit under the subheadings of head and neck reconstruction, cleft lip and palate, craniomaxillofacial surgery, facial palsy, facial trauma, and aesthetic surgery. Most of the evidence presented (86%) is level 4.